Method and apparatus for refrigeration



Feb 26, 1935. E. RICE, JR

METHOD AND APPARATUS FOR RFRIGERATION ll Sheets-Sheet 1 Original FiledJuly 14, 1930 -..nw-.1.. nu...

lldr Feb. 26, 1935. E. RICE, JR .1,992,889

Y METHOD AND APPARATUS FOR REFRIGERATION original Filed July 14, 1930 1lsheets-sheet 2 I l w n l l s s E s l;

furvlfvn vlrl ulllhllll vrrlrfllilrlnllvrlnlllvl/lffr Feb. 26, 1935. E.RICE, JR

METHOD AND APPARATUS FOR REFRIGERATION inal Filed July 14, 1950 llSheets-Sheet 3 Orig Feb. 26, 1935. E. RICE, JR 1,992,889

METHOD AND. APPARATUS FOR REFRIGERATION Original Filed-July 14, 1950 l1Sheets-Sheet 4 'JAL Feb. 26, v192.5'.

E. RICE, JR

METHOD AND APPARATUS FOR REFRIGERATION Original Filed July 14, 1950A llSheets-Sheet 5 Feb. 26, 1935. l E MCE, JR 1,992,889

METHOD AND APPARATUS FOR REFIGERATION originall Filed July 14, 1930 1v1sheetsfsneet 6 Feb. 26, 1935. l E. RlCE, JR 1,992,889

METHOD AND APPARATUS FOR REFRIGERATION original piled July 14, 1930 11sgeets-spet 7 Feb. 26, 1935. E, RICE, JR 1,992,839

METHOD AND APPARATUS FOR REFRIGERATION Original Filed- July 14, 1930 llSheets-Sheet 8 Feb. 26, 1935. E. MCE, JR

METHOD AND APPARATUS FOR REFRIGERATION ll Sheets-Sheet 9 OriginalY FiledJuly 14, 1930 Feb. 26, 1935. E. RICE, JR

METHOD AND APPARATUS FOR REFRIGERATION l1 sheets-sheet 1o Original FiledJuly 14, 1930 Feb. 26, 1935. E R|E, JR

METHOD AND APPARATUS FOR REFRIGERATION Original Filed ,July 14, 1930 llSheets-Sheet 11 Patented Feb. 2s, 193s 4 UNITED s'rfrlzsll PATENT OFFICEY. 1,992,889 f i METHOD AND APPARATUS ron narnia-Enanos Edward liice,Jr., New York; N. Y. Original application July 14, 1930, Serial No.

30 Claims.

A faces of a heat vconductor and is transmitted by the conductor toadjacent' surfaces of the lsolid refrigerant. This is accomplished byvproviding an obstruction in the path of heat flow formed by theconductor whereby the heat 'ow is re`- stricted, or varied as desired.'I'he obstruction consists of any convenient medium of thermal transferresistance and is preferably located between the surface of theconductor presented in the refrigerant containing space and the opposingsurface of the refrigerant. In accordance with the established laws ofphysics, the thickness andinsulating character of this obstructiondetermines' the rate of heat exchange between -the conductor andrefrigerant and thereby the temperature of theextended heat absorbingsurfaces of the conductor, and in turn the temperature of therefrigerated space lor material.

Thev nature and structure of the resistance and of the conductor isdetermind by the character and melting point of the solid refrigerantused and the refrigerating temperatures desired.- 'I'he conductor andrefrigerant containing space are preferably constructed as illustratedso that the solid refrigerant is maintained by gravity in heat exchangerelation with the conductor, although any means maybe used formaintaining the desired relation.

A principal object of the'linvention is to provide a method ofrefrigerating by means of solid refrigerants that shall bemore eilicientthan the priormethods and shall permit of close regulation of theeffective refrigerating temperatures.-

Another object of the invention is to provide a method of'refrigerating'by means of solid refrigerants whereby the eifective4refrigerating temperatures areA to be a substantial degreeindependent of-the volume of .the refrigerant, and to this latter end.. the inventioncontemplates the provision of 'a method for materially increasing the.refrigerating efficiency of relatively small `quantities of 4asolidrefrigerant.

Divided and this application August 25, 1934, Serial No. 741,465

Amilssutu stm another objeet 'of the .invention 1sthe provision of amethod of refrigerating by use of eration of practically any desiredspace whether occupied with a gas (including air), liquid; solid or acombination thereof without actual contact of the refrigerant with thecontents of the space whereby when required the refrigrant may be'entirely divorced from the refrigerated area.

A still futher object of the invention is the provision of refrigeratingapparatus for u'se with a solid refrigerant in whch the principal heattransfer to therefrigerant takes place from the refrigerated space ormass to a condutor of high thermal conductivity and extended surface',and thence conductively to a relatively small surface of the'refrigerantthrough a section` of the conductor sufficiently large .to transmit ltherequired amount of heat for maintaining a predetermined effectiverefrigerating temperature. p

'Ihe invention further contemplates the provision of'refrigeratingapparatus for use interchangeably with solid C02, solid H2O or othersolid refrigerant, in which the principal heat transfer to the solidrefrigerant takes place from the refrigerated area or mass to aconductor of high thermal conductivity and extended srface, Vthenceconductively to a relatively small surface of the refrigerant through asection of the conductor of suillcient size to transmit an amount ofheat required for maintaining a predetermined effective refrigeratingtemperature and in which differences in the melting or sublimingtemperatures of the different refrigerants-maybe compensated by means ofvariable conductor resistances placed between thev conductor and therefrigerant.

Again specifically, and as regards the use of solid refrgerants, such assolid CO2. having a relatively low melting point or` point of sublimation, another object of the invention is to provide a method ofrefrigerating with such refrigerants Awhich shall be both relativelyeilcient and capable of close and accurate regulation of the of outsideatmospheric temperature, of content' A still further object is theprovision of refrigerating apparatus for use with solid CO2 or the, likein which the effective refrigerating temperature is controllable atleast in part by means of insulation set up inan established principalpath of heat travel between the refrigerated area or mass and therefrigerant. u

A still further object -of the invention is to provide a refrigeratingapparatus for use with solid CO2 or the like in which provision is madefor varying the effectiverefrigerating tempera'- ture by means of anobstruction in the principal path of heat travel between therefrigerated area or mass and the refrigerant and in which saidobstruction may be inserted, removed or varied either manually orthermostaticallly during the refrigerating operation.

A further and more specic object of the invention is the provision of amethod of refrigeration by the use of carbon-dioxide ice or the likewhich will permit the automatic maintenance of l' an approximatelyconstant temperature in therefrigerating chamber under varyingconditions of refrigerating chamber, and of ice supply. I

' A further object of the invention is the provision f refrigeratingapparatus for use with CO2 l ice orthe like inwhich the principal heattransescaping CO2 gas.

' fer from the refrigerating chamber and its congas-tight channels awayfrom the contents of the refrigerating chamber, and in which the gasescapes directly to the outside. atmosphere or Y.

through piping of' high thermalconductivity placed in the top of therefrigerating chamber., thus permitting a secondary heat transfer fromtherefrigerating chamber and its contents to the A further object' ofthe Vinvention is to provide a method of and apparatus for refrigeratingby the use of CO2 ice or the like whereby an initial .-aapid chilling ofthe refrigerating chamber or Iits contents may be had when desirable bya com- -paratively rapid melting or sublimation of the ice; andthereafter the required temperature maintained by a much slowersublimation of the ice store. v

A further object 'of the invention is to provide sucha refrigeratinglapparatus for use with CO2 -vt icef or, the like 'that a regulatedtemperature either above or below 'the freezing temperature of water canbe maintained in the--principa1 refrigerating chamber, while in a.second chamber thetemperature is not exactly regulated, but will and inspecific embodiments representing various applications thereof todifferent classes of refrigeration, all as hereinafterv set forth andillustrated inthe attached drawings, in which:

Figure 1 is a diagrammatic sectional view illustrating an embodiment ofmy invention;

Fig. 2 is a fragmentary sectional viewY of the embodiment shown in Fig.1 modified for use with solid CO2 as the refrigerant;

Fig. 3 is a section on the line 3.-3, Fig. 1;

Fig. 4 is a fragmentary sectional view similar to that of Fig. 2 butillustrating the apparatus u sed with a refrigerant composed of frozenbrine;

Fig. 5 is a sectional view illustrating an embodiment of my inventionmodified for use with solid CO2;

Figs. 6, 7, 8, 9 and 10 are fragmentary sectional views illustratingdifferent types of nn construction suitable for use in the practice ofmy invention;

Fig. 11 is a diagrammatic sectional View illustratinga still furtherembodiment of my invention;

Fig. 12 is a section on the line 12'-12, Fig. 11;

Fig. 1'3 is a diagrammatic-sectional view illustrating anotherembodiment of the invention;

Fig. 14 is a diagrammatic sectional view illustrating application oftheprinciples `of my invention to the construction of a container forfrozen product such as ice cream; y

Fig. 15 is a section on the line 15-15, Fig. 14; Fig..16 is adiagrammatic sectional view illustrating a modification of theembodiment illustrated in Fig. 14;'

Fig. 17 is a section on vthe line 17-17, Fig. 16;

Fig. 18 shows another form of refrigerator storage cabinet embodying myinvention;

Fig. 19 is a section on the line 19-19, Fig. 18; f

Fig. 20 is a vertical sectional view showing a further form of singlechamber container made in accordance with my invention;

Fig. 21 is a sectionn the line 21--21, 20;

Figs. 22 and 23 are vertical sectional views illustrating my inventionas embodied in relatively small refrigerator containers;

Figs. 24 and 25 are, respectively, a vertical sectional view and asection taken on the line 25-25, Fig. 24, illustrating a table-orcabinet type of refrigerator made in accordance with myV invention andin condition for use with solid carbon dioxide or other refrigerant ofrelatively.y low melting point;

Fig. 26 is a vertical sectional view through a small type of shippingrefrigerator containerA made in accordance with my invention;

Fig. 27 is a section on the line 2'7-27, Fig. 26;

' Fig. 28 is a plan view of another form of refrigerator employing mymethodand apparaus; l

Fig. 29 is a section on line 29-29 of Fig. 28; Fig.- 30 is a4 section online 30--30 of Fig. 29; Fig. -31 is a vertical sectional view through amoded refrigeratorstructure;

Fig. 32 is a section on line 32--32 of Fig. 31;

Fig. 33 is a horizontal sectional view of a further modied form of theinvention. taken on the line 33-33 of Fig. 34;

Fig. 34 is a section online 34--34 of Fig. 33; Y

Fig. '35 is a. fragmentary bottom plan view of a conductor` plateconstructed for`use in my apparatus;

. Fig. '36 is a fragmentary' modified view of a slightly modified formof a conductor plate wherein the vanes are transversely corrugated toincrease the conduction surface thereof;

Fig, 37 s a fragmentary side elevation of the plate illustrated in thevertical corrugation of the vanes for the same purpose;

Fig. 38 is a front elevation of a household refrigerator constructed inaccordance with my invention and adapted dfor making water ice cubes andstorage of frozen products;

Fig. 39 is a horizontal sectional View on line 39-39-'of Fig. 40;

Fig; 40 is a vvertical sectional view on line 40-40 of Fig. 39; f

Fig. 41 is a horizontal sectional View taken on line 41-41 of'Fig. 42and illustrating a modication of a structure, such as shown in Figs. 38to 40, to produce aj circular refrigerator having rotating shelves;41Fig. 42 is` a section on the line42 -42 of Fig.

Fig. 43 is a fragmentary vertical sectional view illustrating amodification of the invention com,

. meat, fish and other foodstus /also embodying Fig. 45 is a horizontalsectional view, and

Fig. 46 is a vertical sectional view on the line 46-46, Fig. 45,illustrating my invention as applied to refrigeration of relativelysmall truck bodies;

4o' shown in the immediately preceding figures in j .eration of anyenclosed space;

than-any other form of refrigerant.

Fig. 47 is a vertical sectional view of a refrigerating unit made inaccordance with Amy invention and lof a type applicable to the refrigFig. 4a is a section on'the une 1c-4a, Fig. 47; and

Fig. 49 is a diagrammatic horizontal sectional view illustrating theuse. ofaunit of the'type refrigerating the various compartments of atruck or `foar. f

Water ice or solid H2O is more Widely used One of thelprincipaldrawbacks in the prior methods of using this refrigerantor,l infact, any 4solicl refrigerant is .that although any given 'mass of. therefrigerant, no matter how small, has a fixed refrigerating. value; yetthe smaller the mass becomes, the slower its refrigerating actionbecomes also. 'I'his is due to the fact that the' heat given noconsideration, .and no effort has been inferior results.

made to compensate for the. rapid decrease in efliciency as therefrigerant loses volume Land surface area. As a result, a great deal ofice is constantly being used 'with very indifferent or One reason thatthe mechanical household refrigerator has progressed so l'rapidly isbecause the ordinary water ice refrigerator cannotmaintain satisfactoryrefrigeration unless it is contin- .ually serviced and kept practicallyfull of ice at For the same reason, -a largev andbrine through4 themetal container, however, is growing eldfor refrigeration of foodstuffsin not as constant and controllable as in the direct 75' all times;

motor transportation has avoided the use of water ice and other Vsolidrefrigerants. Practically the only method attempted to improve theeiliciency of .water ice as a refrigerant has been the use of salt, amethod of limited application which apparently cannot be greatlyextended.

I have discovered that the principal obstacles .to the efficient use ofwaterice and other solid refrigerants can-be largely overcome if theheat from the space or material to be refrigerated is picked up bycomparatively extended surfaces of a metal heat conductor, such ascopper, aluminum -or iron, and transferred through a subl stantial crosssection of the metal conductor directly to. a surface of the body of icewith which the metal conductor is either in immediate contact or'insuitable conductive relation. I have 'found that by this method, the icecan be meltedl at practically a vconstant rate, thus providing aconstant effective refrigerating temperature practically independentv ofthe volume of the refrigerant, and even with extremely small masses ofthe latter. I have found also that the refrigerant can be melted at analmost inconceivable rate when large amounts-of heat are passed over theextended metal surfaces. a. suflicient cross section of the conductormetal, as small as thirtyA square inches of contact surface with 'therefrigerant will suilice to melt enough water ice to keep agood'household re' .frigeratorbelow 50 F. even on the top shelf in thewarmest weather; and after the doors havev been opened as long as threeminutes; this refrigerator will return to Vits original lowtemperaturewithin twenty minutes or one-half hour. It is essential inthe practice of my invention that the solid refrigerant be maintained incondlrctive relation with a substantial metal conductor'having asuitably extended surface area 4in the refrigerated space.

While the invention is of great importance in conjunction with the useof water ice, it is also of great value in the use of all other solidre-` .-frigerants, such as s olid carbon dioxide and frozen brine. Theapparatus embodying my invention need vary only slightly to meet therequirements lof the particular kind -of refriger. ant Vand the type ofrefrigeration required. If,

for example, refrigerating temperatures around` 35 to 45 F. vare desiredand water ice is to be used by reason of its cheapness and availability,then a relatively large amount of extended conductor or n surface willbe required because of` the small temperature/differential betweenthevtemperature diiferential be maintained between the conductor and. therefrigerated space. Obviously if temperatures are wanted near or belowthe melting point of water ice, then some lother solid refrigerant maybevused with a sufflciently lowmelting or subliming point that the 1conductor 'can be put at a temperature affording the differentialrequired to maintain the refrigeration wanted. Frozen brine may lbe usedes-i vpecially when put up in small and easily. handled units inliquid-tight metal containers. heat-transferred-'from the yconductor tothe-solid contact of water ice with the conductor or the contact ofcarbon dioxide ice with the conductor" through a known amount ofconducting resistance, as hereinafter more specifically set forth.However, as the frozenbrine can be provided with a melting pointpractically anywhere between 32 F. and considerably below zero and hasnow come into more common use and also is comparatively cheap, it isapparent that it Will have a limited use as a solid refrigerant means inmy method of refrigeration. Of course, frozen brine directly in solidstate can be used `in the same way as water ice or carbon dioxide ice bypermitting the melted brine tov drain oi.

When using solid refrigerants such as Vcarbon dioxide ice with atemperature considerably below the melting point of water ice, the useof predetermined known conductor resistances interposed between theconductor and the refrigerant is an important part of my method, as itaffords a large degree of control over the action of -the refrigerantand a quick convenient method of varying the temperature ofthe extendedconductor surface, and thusthe effective refrigerating temperature.

It will be understood that for maximum control of refrigeration, withthis type of refrigerant it is desirable to limit so far as feasibletransfer of heat from the 'refrigerated space or mass to that passingthrough the conductor. This can be accomplished by providing adequateinsulation preventing transfer by radiation or by other than conductionthrough the selected conductor. By thusV establishing a principal andpractically sole path of transfer and utilizing in conjunction therewithsuitable known resistances,'a substantially perfect control may beobtained. This method of controlalsoaifords a simple method forproviding apparatus suitable for use with refrigerants such as water iceand i carbon dioxide ice having widely different melting points. Thus asingle refrigerating apparatuscan be built that can use as a refrigeranteither carbon dioxide or water ice or frozen brine, or, in fact, anysolid refrigerant', and that can maintain practically any requiredtemperature under constant outside temperature conditionsvwithin thelimits .ofthe particular refrigerant used by a simple manipulation ofconductor resistance interposed between the conductor and therefrigerant, and by providing in the same apparatus either manually orthermostatically-'operated means to regulate the convection currentsfrom the extended conductor surfaces or fins, the required temperaturecan bel maintained irrespective of normal outside temperaturevariations.

In Figs. 1 to 4, inclusive, I have illustrated application of theinvention to a refrigeratorof the overhead icing type. In this instance,the.

casing 25 has in its interior and upper portion a refrigerant-supporting.shelf 426 which hinclines fromopposite sides towards the center wherebya solid refrigerant placed thereon has a tendency to gravitate towardthe conter. From the depressed mid-section Ia drain-pipe 27 extendsdownwardly passing between the ns and inv contact with the modified foruse with solid carbon dioxide. In.

this instance, conductor resistance in the form of sheets 31 ofheat-insulating character is interposed between the ice and theconductor shelf 26. Also the solid carbon dioxide is completelysurrounded by insulation 32. The refrigerant is in conductive relationwith the conductor 26 through the resistance 31, which is ofpredetermined value and selected to maintain a predetermined effectiverefrigerating temperature. limation may escape through the pipe 27. Itwill be noted both as regards the use of waterice and dry refrigerant, aconductive relation between the refrigerant and the conductor 26 ismaintained.

In Fig. 4, Ihave illustrated the same apparatus used with frozen brinecontainers 33. These containers with the brine in the solid state aresupported upon the shelf `26, suitable conductor resistance 31 beinginserted between .the Vconductor 26 and thel said containers, and thelatter also being surrounded by suitable insulation 32. In thisinstance, the drain pipe from the shelf 26 is eliminated.

Gases of sub- Fig. 5 shows a type of conduct-or of primary down theupright side of the casting to the bottom or ice-supporting wall.Interposed between the solid carbon dioxide and this lower wall is asuitably selected vconductor resistance 4.2, and the ice is alsosurrounded by suitable insulation 43.

In Figs. 6 to 10, inclusive, I have illustrated various types of finconductors which have been found suitable in the practice of myinvention.

The form of conductor illustrated in Fig. 6 is one that can beconveniently used for household refrigeration purposes, this being madeup from a number .of bent copper sheets 45 soldered together at thepoints designated 46 so as to present a substantially iiat conductorplate surface for contact with the solid refrigerant and a considerablyextended fin surface for contact with the convection currents;

Fig. 7 shows a similar construction in which the outer ends 47 of theprojecting iin portions are turned inwardly toward each other so as toafford the same amount-of contactsurface in a more restricted space.

Fig. 8 shows a more efficient type of conductor in which thin copperfins 48 are soldered or vwelded to a heavy copper conductor plate 49.

Fig. 9 shows a still more eicient but more Aexpensive form of conductorconsisting of a solid aluminuiriK plate 51 with thin copper fins 52secured to the' aluminum plate by-casting the latter on the ns.

Fig. 10 shows an all-aluminumin conductor formed of a single casting. Y

In Fig. 1l, I have illustrated my invention as applied to a water cooleremploying solid carbon dioxide as the refrigerating medium. In thisinstance, the conductor forming an essential part of the device consistsof a solid aluminum or copperlreceiptacle 55 which is embedded in solidinsulation 56. A chamber 57 is provided in the insulation 56 for thewater or other liquid to be n perature of the conductor.

' ing ice cream, frozen foods or the like.

cooled. This chamber, as shown in Fig. 12, extends completely around thesides of the receptacle 55, but is spaced a suicient distance from thesaid conductor to maintain a desired temperature of the liquid for anypredetermined tem- This temperature in turn is controlled bythethickness of conductor resistance 58 interposed between the solidcar` bon dioxide ice and the bottom wall of the conductor. With anarrangement of'this character, I have found it possible tomaintainsubstantially any desired temperature of the liquid within the container57 by simple variation in the thickness of the conductor resistance 58which modifies the conductive relation between the conductor 55 and therefrigerant. It Will. be noted that in this instance the conductor whilehaving the necessary extended surface is not provided with ns, and thatfurther the .surfaces of the conductor are not in direct contact withthe liquid to be cooled, but are in conductive relation` therewiththrough the insulation separating the walls of the liquid container fromthe said conductor.

Fig. 13 shows a similarly constructed water cooler with the addition ofa storage space 60 located below the bottom of the conductor, it beingpossible to maintain this space at practically any required temperatureby variation in the thickness of the insulating member 70 whichconstitutes conductor resistance between the space and the bottom of theconductor 55. I

A more or less similar form of conductor is shown in Figs. 14 and l5,which show a cabinet suitable for use with solid carbon dioxide forstor- In this instance, the conductor consists of a solid aluminumcasting 62, this casting comprising a base 63 and four cylindricalvertical containers 64. In this instance, the walls of the portions 64constitute the necessary extended surface area, provision being made forsupportingthe refrigerant upon the base between the said portions 64, asshown in Fig. 15.- For this purpose, the refrigerant may: be supportedwithin a vertical metallic or other container open at the bottom topermit the ice to come into conductive relation with the base portion 63of the conductor, from which it may be separated by a suitable conductorresistance member 65 selected to afford a desired temperature within thereceptacle 64 in which the refrigerated material is stored. The entireconductor casting is surrounded by a suitable insulating casing 66, andprovision is made in the form of removable cover plates 67 for affordingaccess tothe interior of the container 64.

In Figs. 16 and 17, I have illustrated a similar type of refrigeratingapparatus which in addition includes storage -chambers or receptacles 67embedded in the insulating casing 66 in suitably spaced relation to the'sides of the container 64, these compartments 67 being readily kept at.

a non-freezing temperature and being suitable for holding Water or othersubstances or mate/- rials at a relatively low but non-,freezingtemperature.

In Figs. 18 and y19, I show a form of refrigerating storageboxlconvenient for use on store counters and under similar conditions.In this instance, the storage space is surrounded on three sides and thebottom by the conductor 85, and the heat is picked up as it4 comesthrough the v walls of the storage box and also from the conductor, andthence to the .refrigerant shown asv blocks of solid carbon dioxide,which is separated fromv the conductor by the conductor resistance 86generally used with this refrigerant. It will be noted that the chamberwhich holds the refrigerant is separated Ifrom the storage chambers `onthe base of the conductor with the usual interposed conductor resistance93. A small removable shelf 94 is placed over the ice to support the icecream can or other materials to be stored. A vent 95 affords escape ofthe sublimed gases or meltage.

In the embodiment shown in Fig. 22, a small storage box adapted for useprimarily with CO2 ice is shown. In this instance, the conductor takesthe form of a rectangular container 96 which is open at one side, andprovision is made for placing the refrigerant on the top wall of theconductor as illustrated, the usual conductor resistance 97 beingprovided. Access to the ice chamber is afforded through a removablecover 98 in the insulating casing 99, and access to the refrigeratingchamber is provided by a suitable removable cover member (not shown)located in the side of the said casing.

Fig. 23 shows still another form of small storage box in which theconductor 101 is in the form .of a removable storage bin, this conductorbeing made preferably f copper or aluminum. Access to the storage spaceis afforded through a removable cover 102 in the top of the insulatingcasing 103, and this top portion 104 of the casing is also hinged at 105yto permit the entire top to be turned back to permit removal of theconductor 101. The refrigerant in this instance is supported upon ashelf 106 which is movable within the casing and which has legs 107which project through openings in the bottom of the casing and rest uponthe oor or other supporting surface. As the CO2 ice sublimes, the entirecasing settles downwardly around the shelf 106, wherebythe refrigerantis maintained in continuous conductive relation with the bottom of the iconductor 101. The usual conductor resistance 108 is interposed betweenthe refrigerant and the bottom of the conductor.

In Figs. 24 and 25, I have illustrated a large table or cabinet type ofrefrigerator adapted for use either with CO2 ice or water ice and inwhich provision is made for obtaining in the three separate compartmentsthree different temperatures, when CO2 ice is used, or of twotemperatures when water ice is employed. This refrigerator consists ofan outer insulated casing 111 having in the top a chamber for a,refrigerant, the opposite sides and the bottom of which are constitutedby a channel-shaped conductor 112. 'Ihe side walls of this conductor areprovided with outwardly projecting fins 113, and the bottom wall atendency of the solid refrigerant to move by gravity towards thevertical fin walls. Access to this refrigerating chamber is had througha' removable cover 114. Three refrigerating cham- `is slightly elevatedtowards the center to create bers are provided numbered 115, 116 and117, respectively, the chamber 116 being located directly below therefrigerant chamber.V Baflles 118 in the chambers and 117 extendvertically and preferably in Contact with the outer edges of the ns 113whereby a convective circulation is set up in which the air movesdownwardly between the ns and against the side walls of the conductor.The chamber 116 is separated from the other chambers by insulating walls119, and in one or both of the chambers 115 a valve 120, which may beoperated manually or automati- -cally from a suitable thermostaticactuator, is

provided for controlling the movement of the con-- vection currentsdownwardly past the Walls and ins of the conductor. Where carbon dioxideice is used, the refrigerant is surrounded in the refrigerating chamberon four sides and the top by suitable insulation 121, while the ice isseparated from the bottom of the conductor by means of suitableconductor resistance 122. 'I'he temperature in the chamber 116 iscontrolled by the thickness and character of the conductor resistance,whereas the temperatures in the compartments 115 and 117 are controllednot only by the conductor resistance, but also by the thickness andcharacter of the insulation 121, and may be still further controlled bymanipulation of the valve 120.

Figs. 26 and 27 illustrate a small shipping refrigerator box in whichthe conductor 126, which may suitably be made of copper or aluminum, ineffect lines the four walls and bottom of the casing 127. This form ofrefrigerator is particularly suited for use with CO2 ice, and it will benoted that the usual protective Vinsulation 128 and conductor resistance129 are provided. Referring to Figs. 28, 29 and 30, numeral 140designates a refrigerating chamber having access doors 141 in the upperwall 142 thereof. The

chamber walls are, of course, insulated in anyV usual or preferredmanner and the upper wall`14t2 has formed therein an opening 143.Extending into the refrigerating chamber through this opening is aninsulated cabinet 144 approximately gas tight having an open top closedby an access door 145. The bottom wall 144a of this cabinet has imposedthereon a conductor plate 146 which may be conveniently constructed fromcopper, aluminum or some other metal having a suitably high factor ofthermal conductivity. The edges of this plate proa'ect through thecabinet walls and are provided withvvertically-extending varies 147projecting upwardly along the side walls of the cabinet and preferablyconstructed integrally with the plate 146. These vanes, as evidenced byFigs. 35, 36 and 37, may be either plane, as in Fig. 35, or transverselyor longitudinally corrugated, as indicated at 147 and 1471),respectively, in Figs. 35 and 36, the latter constructions proividing anincreased surface for contact with convection currents.

Opposing the outer edges of the vanes are insulated walls 148 whichcombine with the cabinet to provide channels 149 through whichconvection currents may pass. The lower ends of these channels areclosed by valves 150 regulated through a thermostat 151. In the presentinstance, the valves are illustrated as pivotally connected to the lowerwall of the cabinet at 152 and connected to the movable element 153 ofthe thermostat by a linkage generallyfdesignated at 154.

From the interior of the cabinet a vent tube 1515 is led through thewall of the refrigerating chamber 140. This vent tube is made of metalof a high thermal conductivity, preferably copper, and includes a coil155e disposed in chamber 140 for contact with the 'convection currentsof the chamber, preferably near the top of the chamber and where warmpockets are liable to occur. The outlet of the vent tube is placed belowthe inlet in order to induce a ready flow of CO2 gas by siphoning, andis preferably equipped with a regulating valve which may be convenientlyhoused in a recess formed in the wall of the cabinet.

The interior of the cabinet is preferably subdivided into a plurality ofsections by vertically extending partitions -159 constructed ofinsulating material. 'I'hese partitions are in the present instanceillustrated as two in number so that three ice spaces are formed.` Thebottoms of these ice spaces are formed by the plate 146 and upon theplate in the bottom of each ice space insulation 160 may be disposedbetween the ice and the plate, the thickness of this insulation varyingin accordance withthe conditions under which the refrigerator is to beemployed'. Insulation 160 is removable` and of variable thickness and itwill be obvious that if two of the compartments have in the bottomsthereof insulation 160 of a considerable thickness while a thirdcompartment has no insulation as suggested in Figs. 28, 29 and 30, or arelatively thin insulation as suggested in Fig. 34

the ice of this latter compartment will be sublimed more rapidly thanthat in the remaining compartments so that the ice of this compartmentVacts as an initial chilling supply While that of the remaining-compartments acts as a reserve supply. Thus the first mentioned icesupply serves to rapidly reduce the temperature of the chamber wheninitiallyr placed in operation or when a rapid reduction of temperaturetherein is necessary following an opening of the access doors '141.

If, for example, goods are placed in the re-v frigerator at their normaltemperature and must be rapidly chilled, the insulation 160 may becompletely removed from one of the compartments so that the ice in thiscompartment ,will act very rapidly to reduce the temperature of thechamber and to chill the goods to the desired point. The desiredtemperature having been attained, the ice in the remaining compartmentsis held in reserve to maintain thistemperature, thus materiallyincreasing the period over which refrigeration is possible andparticularly adapting the apparatus for use in transportation ofperishable goods where facilities for replenishing the "ice store arepoor.

When precooled products are placed in the refrigerating chamber, thenthe bottoms of all of the compartments may be provided with insulation,thus providing a maximum period of refrigeration for a given ice supply.By varying the extent to which the bottoms of the comspaces of therefrigerating chamber are preferably separated from the cabinet spacesby foraminous screens 162. A

The principal amount of the heat used in melting, or subliming the iceis transferred by'conthe insulated chamber walls and doors.

vectionvfrom the storage chamberand its contents to the verticallyextending vanes 147, thence conductively to the plate 146, thenceconductively directly, or through insulation 160 to the ice, A smalleramount of heat is transferred by conduction through the insulations ofthe "ice cabinet and walls 148, and by internal convectioncurrents'within the ice cabinet and space 147a. Control of thetemperature of vthe storage chamber and contents is secured in part bypredetermined fixed variations of the size and character of theconduction plate 146 and vanes 147, and of the insulations 144, 144e,148, 150 and However, actual changes in temperature in the contents ofthe storage chamber during reduction to a desired level, as well asclimatic and artificial changes in temperature outside the storagechamber may require a further means for securing aV constant temperatureinside the chamber. This is achieved by the thermostatic or manualcontrol of the convection currents through channels v149 andtransferring more or less heat to conduction vanes 147 and plate 146. Bythese several means a variation of the rate of subliming or melting thecarbon-dioxide ice of asv much as 1,000% can be attained which I believeis sufficient to accomplish the objects of this invention.

The structure of Figs. 31 and 32 is substantially identical with that ofFigs. 28, 29 and 30, with the exception of the fact that the chamber 140has its access door 141a mounted in the 4side wall thereof vand thatcommunication between the channels 149 and the storage space in theupper endsA ofthese channels instead of being made only through openings163, formed in the insulating walls, includes one or more ducts 164opening at the inner end through the wall of channel 149 and having theouterend disposed adjacent to the wall of the chamber 140 or where warmpockets are likely to occur. A further slight modification ofthe'control of the channelis employed in that the valves 150a instead ofbeing supported by the cabinet, as in Figs. 28, 29 and 30, are directlysupported from and secured to the movable member 153 of the thermostat.The thermostat has further associated therewith bafile shields 165 whichprevent chilled air, descending from the convection channels, fromdirectly contacting thermostat 151 and thus causing too early a closingoperation of the valves 150a. I

The form shown in Figs. 33 and 34 is identical with the structure ofFigs. 31 and 32, with the exception of the fact that conduction vanesare provided entirely about the cabinet walls and entrance to theconvection channels is largely through ducts 164a, the intake ends ofwhich are disposed adjacent to the vertical Walls of the chamber 140.

In Figs. 38, 39 and 40, I have illustrated refri'geration apparatusparticularly adapted for household uses and embodying means for pro? ingpans 168 for the formation of ice cubes or used in freezing confectionsor for storing frozen ply may rest at its lower end directly upon theplate 146, or uponportable insulation 160A as de,- scribed above. Theice cube and frozen storage compartment 166 may, however,belconveniently combined with structures embodying several verticalcolumns of "ice as suggested in Fig. 43.

In Figs. 41 and 42, the construction ofi Figs. 38 to 40 is modified topermit its adaptation Ato a circular refrigerator having rotatingshelving units 171, the rotation of which will bring storage intoalignment with an access door 172 which aligns with the access door ofthe freezing chamber 166.

In Fig. 44 is illustrated an apparatus made in accordance with myinvention adapted forquck freezing of meat, fish and similar products. Acasing 203 has established therein a conductor plate 204, this platebeing adapted to slide vertically in the casing. Depending from theplate 204 is an insulating apron 205 which fits more or less closelyaround a post or ram 206 also preferably of insulating material. When arefrigerant is placed between the upper end of the ram 206 and the plate204 and within the space sur# rounded by the apron 205, it will beapparent that the plate will be supported by the refrigerant, and thatas the latter melts or sublimes, the plate will move downwardlyQso thatthe conductive relation between the plate and the refrgerantwill remainconstant. AWhere a refrigerant such as solid CO2 is employed,temperatures may best be controlled by a conductor resistance 207inserted between the refrigerant and the plate as yillus- In thisillustration, wheretrated. An upper plate 208 is' provided having at thetop an enclosed insulated space 209 for reception of a refrigerant whichis held in conductive relation to the plate 20-8. This plate `208l restsupon the material to be frozen, which latter in turn rests upon theplate 204, so that the material is confined between the two cold plates,insuring rapid freezing. Where arefrigerant of the type of solid CO2 isused, it is preferred to employ a conductor resistance 211 which isinterposed between the plate 208 and the refrigerant as illustrated. l

In Figs. and 46, a refrigerating system is illustrated suitable forsmall truck bodies and the like and adapted for refrigeration withpractically any type of solid refrigerant. The body 221 in this instancehas a chamber 222 at one endA and in the upper portion for reception ofthe refrigerant, the bottom and front wall of this' space beingconstituted by a suitable angular conductor plate 223, and the saidfront wall being provided with fins 224 which projectinto the interioror refrigerated area'of thel truck.` The space directly `under thebottom of the -conductor plate 223 is enclosed by a partition 225 andconstitutes a cold compartment whose temperature may be maintained at arelatively low point. A false wall or baffle 226 is provided in theinterior of the body which forms a channel for the circulation of theconvection currents, as in' dicated by the arrows, the circulating airpassing downwardly over the upright face of the conductor 223 andbetween the fins 224.v I also may provide in this instance a valve 227in the air .passage whereby the circulation of air may be controlledeither manually or'by a suitable thermostat, thereby affording a furthercontrol of the interior temperature of the truck. Where, as illustrated,a refrigerant such as solid-carbon dioxide is employed, this refrigerantwill be surrounded by an insulating sleeve 228 and separated from `thebottom of the conductor memberby a suitable conductor resistance element229. The temperatures may be controlled by regulating thethickness-andcharacter of the-conductor resistance and of vtheinsulating sleeve 228.

. Where Water ice is employedthe sleeve 228 and conductor resistance 229maybe eliminated. It will be noted that in this case also I employ onthe top of the truck body a suitable radiation.

shield 231.

Figs. 47 and 48 illustrate a unit of portable character which may beapplied Asuccessfully to the refrigeration of any desired enclosedspace.The unit consists of t-he .usual thermal conductor 255 in the form of acontainer, three side walls of which are provided with outwardlyprojecting ns 256 and being provided also with baffles 257 secured tothe outer edges of the fins and extending to a point short of the topsof the latter. The refrigerant may be .introduced through the side ortop of the conductor, and is maintained by gravity in conductiverelation to the bottom wall of the latter. Where solid carbon dioxide isused, an insulating sleeve 258 is provided and also a suitable conductorresistance 259 separating the refrigerant from the conductor upon whichit rests. Means is provided in the form of a duct 260 for permittingescape of the sublimed gases. An application of this unit is illustratedin Fig. 49, which shows in horizontal section a four-compartment car ortruck, each compartment being provided with one of the aforedescribedunits preferably suspended adjacent the top and at one side of thecompartment.

l. The method of refrigerating by means of a solid refrigerant, whichconsists in providing between the refrigerant and the region to berefrigerated a principal path of heat transfer in the form of a thermalconductor capable of effecting a transfer of heat from said.l region tothe refrigerant at a rate higher than that required for a giveneffective refrigerating temperature, and interposing between saidconductor and the refrigerant a medium of thermal-transfer resistance tothereby control and regulate the rate of heat exchange between therefrigerant and the conductor.

2. The method of refrigerating by means of a solid refrigerant, whichconsists in providing between the refrigerant and the region to berefrigerated a principal path of heat transfer in lthe form of a thermalconductor capable of effecting a transfer of heat from said region tothe refrigerant at a rate higher than that required for a giveneffective refrigerating temperature, and interposingbetween saidconductor` and the refrigerant a medium of thermal-transfer resistancewhereby the rate of heat exchange between the conductor and therefrigerant is restricted.

3. The method ,of refrigerating by means of a solid refrigerant, whichconsists-in providing between the refrigerantand the region to berefrigerated a principal path of heat transfer in the form of a thermalconductor capable of effecting a transfer of heat from said region tothe refrigerant at a rate higher than that required for a giveneffective refrigerating temperature, and interposing in said path amediumv of thermal-transfer resistance to thereby control and regulatethe rate of heat exchange between the refrigerant and the region to berefrigerated.

4. In a 'refrigerating process' the method which consists in taking upheat from the refrigerated area or mass by relatively extended surfacesof a highly conductive metal, conducting this heat bymeans of theconductor to a relatively small surface of a solid refrigerant, andrestricting theexchange of heat between the conductor and therefrigerant by means of a medium of thermal transfer resistance locatedbetween the conductor and the refrigerant.

5. A refrigerator chamber having therein a thick-Walled, gas-tight,cast-metal container Asubstantially without exterior insulation, and

having exterior metal surfaces exposed for heat labsorption and moisturedeposit from the atmosphere of the refrigerated space, and means forsupporting solid'carbon dioxidewithin the container in heat exchangerelation but out of contact with the metal of said container.

6. Apparatus for refrigerating by the use of carbon-dioxide icecomprising a chamber, an insulating cabinet therein and` sealedtherefrom and adapted for the reception of carbon-dioxide ice, a heatconductor having portions disposed interiorly and exteriorly of thecabinet, and vertical partitions within the cabinet subdividing thespace therein into compartments, said conductor forming the bottoms ofsaid compartments, and insulation removably superimposed upon saidconductor without eliminating heat transfer between said conductor andthe ice in said compartments.

'7. Apparatus for refrigerating by the use of carbon dioxide icecomprising .a chamber, an

insulating cabinet therein and sealed therefrom and adapted for thereception of carbon dioxidel ice, a heat conductor having portionsdisposed interiorly and exteriorly of the cabinet, said conductorforming the bottom of the ice containing space in said cabinet,andinsulation removably superimposed upon said conductor Withouteliminating heat transfer between said conductor and the ice vin saidcabinet.

8. Apparatus for refrigerating by the use of carbon-dioxide icecomprising a chamber, an insulating cabinet therein and sealed therefromand adapted for the reception of carbondioxide ice, a heat lconductorplate having portions disposed interiorly and exteriorly of the cabinet,insulation removably superimposed upon said plate and reducing withouteliminating heat transfer between said plate and the ice in saidcabinet, and an insulating wall coacting with the cabinet to produce aconvection channel for the chamber in which the exteriorly-disposedportions of the plate extend.

9. Apparatus for refrigerating by the use of carbon-dioxide icecomprising a chamber, an insulating cabinet therein and sealed therefromand adapted for the reception of carbon-dioxide ice, a heat' conductorplate having portions disposed interiorly and exteriorly of the cabinet,said plate forming the bottom of the ice containing space in saidcabinet, insulation removably superimposed upon said plate and reducingwithout eliminating heat transfer between said plate and the ice in saidcabinet, said plate dividing the cabinet into two sections, and separateaccess doors for said sections.

10. Apparatus for refrigerating by the use of carbon-dioxide icecomprising a chamber, an insulating cabinet therein and sealed therefromand adapted for the reception of carbon-dioxide ice, a heat conductorplate having portions disposed interiorly and exteriorly of the cabinet,said plateforming the bottom of the ice containing space in saidcabinet, insulation removably superimposed upon said plate and reducingwithout eliminating heat transfer between said plate and the ice in saidcabinet, and thermostatically-controlled valve means regulating contactof convection currents in the chamber with the exteriorly-disposedportions of said plate.

11'. Apparatus for refrigerating by the use of carbon-dioxide icecomprising achamber, an insulating cabinet therein and sealed therefromand adapted for the reception of carbondioxide ice, a heat conductorplate vhaving portions disposed interiorly and exteriorly of thecabinet, said plate forming the bottom of the ice containing space insaid cabinet, insulation removably superimposed upon said plate andreducing without eliminating heat transfer between said plate and theice in said cabinet, said exteriorly-disposed portions including vanesextending upwardly along the walls of the cabinet.

12. Apparatus for refrigerating by the use of carbon-dioxide icecomprising a chamber, an insulating cabinet therein and sealed therefromand adapted for the reception of carbon-dioxide ice, a heat conductorplate having portions disposed interiorly and exteriorly of the cabinet,said plate forming the bottom of the ice containing space in saidcabinet, insulation removably superimposed upon said plate and reducingwithout eliminating heat transfer between said plate and the ice in saidcabinet, and thermostatically-controlled valve means regulating contactof convection currents in the chamber with the exteriorly-disposedportions of said plate, said exteriorly-disposed portions includingvanes extending upwardly along the walls of the cabinet.

13. Apparatus for refrigerating by the use of carbon-dioxide icecomprising a storage chamber, an insulated cabinet therein and sealedtherefrom, a heat conductor having portions disposed interiorly andexteriorly of the. cabinet, said cabinet adapted to simultaneouslyreceive a plurality of bodies of ice, and means partially insulatingcertain of the bodies from the conductor.

1 4. Apparatus for refrigerating by the use of carbon-dioxide icecomprising a storage chamber, an insulated cabinet therein and sealedtherefrom, a heat conductor having portions disposed interiorly andexteriorly of the cabinet, said cabinet adapted to simultaneouslyreceive a plurality of bodies of ice, means partially insulating certainof the bodies from the conductor, said conductor subdividing theinterior of the cabinet into two compartments, and separate access doorsfor said compartments. i

15. Apparatus for refrigerating by the use of carbon-dioxide icecomprising a storage chamber, an insulated. cabinet therein and sealedtherefrom and adapted for the reception of car-- bon-dioxide ice, a heatconductor having portions disposed interiorly and exteriorly of thecabinet, and means partially insulating the ice from the conductor.

16. Apparatus for refrigerating by the use of carbon-dioxide icecomprising a storage cham- 5 ber, an insulated cabinet therein andsealed therefrom and adapted for the reception of carbon-dioxide ice, aheat conductor having portions disposed interiorly and exteriorly of thecabinet, means partially insulating the ice from the conductor, saidconductor subdividing the interior of the cabinet into two compartments,and separate access doors for said compartments.

17. Refrigerating apparatus comprising a thermal conductor in the formof a container, an insulating casing for said container, said conductorhaving throughout a conductive capacity capable of maintaining in allparts of the contained space a substantially uniform refrigeratingtemperature by means of a solid refrigerant in conductive 2O associationwith that portion of the conductor forming the bottom of the container,means in said container for supporting a product above said refrigerant,and means located between the r refrigerant and the conductor forregulating and 25 controlling said conductive association.

18. Apparatus for refrigerating by means of/ solid'carbon dioxide ice,which comprises a. thermal conductor in the form ofa container, aninsulating casing surrounding said container, an 30 insulating jacket inthe bottom of said container enclosing the said refrigerant andextending between the refrigerant and the said conductor,

`said conductor having throughout a conductive ductor in the form of acontainer, an insulating casing surrounding said conductor, and arefrigerant-receiving jacket in the bottom of said container extendingbetween the refrigerant and the said conductor whereby the conductiverelation. between the refrigerant and the said conductor is regulated,and said conductor having a conductive capacity throughout insuringmaintenance of all parts'of the interior space of said container at asubstantially uniform predetermined refrigerated temperature.

20. In a refrigerator for use withsolid carbon dioxide, a receptacle forsaid refrigerant in the form of a thermal conductor having a pluralityof walls, each of said walls being associated with a segregated portionof the interior of said refrigerator, and means for conductivelyassociat- `ing the said refrigerant with at least one of said lsaidrefrigerant, 'and variable insulation means for regulating theconductive relation between the said refrigerant and those portions ofthe conductor directly associated with the dierent compaxjtments. I 75

